This invention relates generally to a safety valve for use in hydraulic line system which prevents flow of a working hydraulic fluid above a specific flow rate and more particularly to a safety valve which screws directly into the chute lift cylinder port and the chute lift hydraulic hose of a ready-mix concrete truck. The delivery chute on the rear of ready-mix concrete trucks is conventionally hydraulically raised and lowered. In normal operating use, the chute is often full of concrete and held in position by a hydraulic cylinder.
The hydraulic hose connected to the hydraulic cylinder is subject to wear, damage and deterioration by the nature of its application. Frequent inspections for cuts, abrasions, wear, acid wash damage, etc. are necessary to prevent hose failure during operation. Failure may occur if the hose is not regularly inspected or from damage to the hose occurring on the job. Workers tugging and pulling on a heavy, full concrete chute can cause pressure spikes in the chute life hydraulic hose. Previously damaged hose may potentially break from the pressure spikes. A broken hose results in a sudden pressure loss and the fluid flow is no longer controlled. The sudden loss of pressure causes hydraulic fluid to rapidly flow from the hydraulic cylinder, resulting in the chute crashing downward and potentially seriously injuring workers.
What is needed is a way to prevent the chute from crashing downward due to a sudden loss of hydraulic fluid pressure.